//
// "$Id: Fl_Scrollbar.cxx 8864 2011-07-19 04:49:30Z greg.ercolano $"
//
// Scroll bar widget for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//


#include "Fl.H"
#include "Fl_Scrollbar.H"
#include "fl_draw.H"
#include <math.h>
#include "flstring.h"

#define INITIALREPEAT .5
#define REPEAT .05

void Fl_Scrollbar::increment_cb()
{
	char inv = maximum()<minimum();
	int ls = inv ? -linesize_ : linesize_;
	int i;
	switch (pushed_) {
	case 1: // clicked on arrow left
		i = -ls;
		break;
	default: // clicked on arrow right
		i =  ls;
		break;
	case 5: // clicked into the box next to the slider on the left
		i = -(int((maximum()-minimum())*slider_size()/(1.0-slider_size())));
		if (inv) {
			if (i<-ls) i = -ls;
		} else {
			if (i>-ls) i = -ls; // err
		}
		break;
	case 6: // clicked into the box next to the slider on the right
		i = (int((maximum()-minimum())*slider_size()/(1.0-slider_size())));
		if (inv) {
			if (i>ls) i = ls;
		} else {
			if (i<ls) i = ls; // err
		}
		break;
	}
	handle_drag(clamp(value() + i));
}

void Fl_Scrollbar::timeout_cb(void* v)
{
	Fl_Scrollbar* s = (Fl_Scrollbar*)v;
	s->increment_cb();
	Fl::add_timeout(REPEAT, timeout_cb, s);
}

int Fl_Scrollbar::handle(int event)
{
	// area of scrollbar:
	int area;
	int X=x();
	int Y=y();
	int W=w();
	int H=h();

	// adjust slider area to be inside the arrow buttons:
	if (horizontal()) {
		if (W >= 3*H) {
			X += H;
			W -= 2*H;
		}
	} else {
		if (H >= 3*W) {
			Y += W;
			H -= 2*W;
		}
	}

	// which widget part is highlighted?
	int relx;
	int ww;
	if (horizontal()) {
		relx = Fl::event_x()-X;
		ww = W;
	} else {
		relx = Fl::event_y()-Y;
		ww = H;
	}
	if (relx < 0) area = 1;
	else if (relx >= ww) area = 2;
	else {
		int S = int(slider_size()*ww+.5);
		int T = (horizontal() ? H : W)/2+1;
		if (type()==FL_VERT_NICE_SLIDER || type()==FL_HOR_NICE_SLIDER) T += 4;
		if (S < T) S = T;
		double val =
		        (maximum()-minimum()) ? (value()-minimum())/(maximum()-minimum()) : 0.5;
		int sliderx;
		if (val >= 1.0) sliderx = ww-S;
		else if (val <= 0.0) sliderx = 0;
		else sliderx = int(val*(ww-S)+.5);
		if (Fl::event_button() == FL_MIDDLE_MOUSE) area = 8;
		else if (relx < sliderx) area = 5;
		else if (relx >= sliderx+S) area = 6;
		else area = 8;
	}

	switch (event) {
	case FL_ENTER:
	case FL_LEAVE:
		return 1;
	case FL_RELEASE:
		damage(FL_DAMAGE_ALL);
		if (pushed_) {
			Fl::remove_timeout(timeout_cb, this);
			pushed_ = 0;
		}
		handle_release();
		return 1;
	case FL_PUSH:
		if (pushed_) return 1;
		if (area != 8) pushed_ = area;
		if (pushed_) {
			handle_push();
			Fl::add_timeout(INITIALREPEAT, timeout_cb, this);
			increment_cb();
			damage(FL_DAMAGE_ALL);
			return 1;
		}
		return Fl_Slider::handle(event, X,Y,W,H);
	case FL_DRAG:
		if (pushed_) return 1;
		return Fl_Slider::handle(event, X,Y,W,H);
	case FL_MOUSEWHEEL :
		if (horizontal()) {
			if (Fl::e_dx==0) return 0;
			int ls = maximum()>=minimum() ? linesize_ : -linesize_;
			handle_drag(clamp(value() + ls * Fl::e_dx));
			return 1;
		} else {
			if (Fl::e_dy==0) return 0;
			int ls = maximum()>=minimum() ? linesize_ : -linesize_;
			handle_drag(clamp(value() + ls * Fl::e_dy));
			return 1;
		}
	case FL_SHORTCUT:
	case FL_KEYBOARD: {
		int v = value();
		int ls = maximum()>=minimum() ? linesize_ : -linesize_;
		if (horizontal()) {
			switch (Fl::event_key()) {
			case FL_Left:
				v -= ls;
				break;
			case FL_Right:
				v += ls;
				break;
			default:
				return 0;
			}
		} else { // vertical
			switch (Fl::event_key()) {
			case FL_Up:
				v -= ls;
				break;
			case FL_Down:
				v += ls;
				break;
			case FL_Page_Up:
				if (slider_size() >= 1.0) return 0;
				v -= int((maximum()-minimum())*slider_size()/(1.0-slider_size()));
				v += ls;
				break;
			case FL_Page_Down:
				if (slider_size() >= 1.0) return 0;
				v += int((maximum()-minimum())*slider_size()/(1.0-slider_size()));
				v -= ls;
				break;
			case FL_Home:
				v = int(minimum());
				break;
			case FL_End:
				v = int(maximum());
				break;
			default:
				return 0;
			}
		}
		v = int(clamp(v));
		if (v != value()) {
			Fl_Slider::value(v);
			value_damage();
			set_changed();
			do_callback();
		}
		return 1;
	}
	}
	return 0;
}

void Fl_Scrollbar::draw()
{
	if (damage()&FL_DAMAGE_ALL) draw_box();
	int X = x()+Fl::box_dx(box());
	int Y = y()+Fl::box_dy(box());
	int W = w()-Fl::box_dw(box());
	int H = h()-Fl::box_dh(box());
	if (horizontal()) {
		if (W < 3*H) {
			Fl_Slider::draw(X,Y,W,H);
			return;
		}
		Fl_Slider::draw(X+H,Y,W-2*H,H);
		if (damage()&FL_DAMAGE_ALL) {
			draw_box((pushed_==1) ? fl_down(slider()) : slider(),
			         X, Y, H, H, selection_color());
			draw_box((pushed_==2) ? fl_down(slider()) : slider(),
			         X+W-H, Y, H, H, selection_color());
			if (active_r())
				fl_color(labelcolor());
			else
				fl_color(fl_inactive(labelcolor()));
			int w1 = (H-4)/3;
			if (w1 < 1) w1 = 1;
			int x1 = X+(H-w1-1)/2;
			int yy1 = Y+(H-2*w1-1)/2;
			if (Fl::is_scheme("gtk+")) {
				fl_polygon(x1, yy1+w1, x1+w1, yy1+2*w1, x1+w1-1, yy1+w1, x1+w1, yy1);
				x1 += (W-H);
				fl_polygon(x1, yy1, x1+1, yy1+w1, x1, yy1+2*w1, x1+w1, yy1+w1);
			} else {
				fl_polygon(x1, yy1+w1, x1+w1, yy1+2*w1, x1+w1, yy1);
				x1 += (W-H);
				fl_polygon(x1, yy1, x1, yy1+2*w1, x1+w1, yy1+w1);
			}
		}
	} else { // vertical
		if (H < 3*W) {
			Fl_Slider::draw(X,Y,W,H);
			return;
		}
		Fl_Slider::draw(X,Y+W,W,H-2*W);
		if (damage()&FL_DAMAGE_ALL) {
			draw_box((pushed_==1) ? fl_down(slider()) : slider(),
			         X, Y, W, W, selection_color());
			draw_box((pushed_==2) ? fl_down(slider()) : slider(),
			         X, Y+H-W, W, W, selection_color());
			if (active_r())
				fl_color(labelcolor());
			else
				fl_color(fl_inactive(labelcolor()));
			int w1 = (W-4)/3;
			if (w1 < 1) w1 = 1;
			int x1 = X+(W-2*w1-1)/2;
			int yy1 = Y+(W-w1-1)/2;
			if (Fl::is_scheme("gtk+")) {
				fl_polygon(x1, yy1+w1, x1+w1, yy1+w1-1, x1+2*w1, yy1+w1, x1+w1, yy1);
				yy1 += H-W;
				fl_polygon(x1, yy1, x1+w1, yy1+1, x1+w1, yy1+w1);
				fl_polygon(x1+w1, yy1+1, x1+2*w1, yy1, x1+w1, yy1+w1);
			} else {
				fl_polygon(x1, yy1+w1, x1+2*w1, yy1+w1, x1+w1, yy1);
				yy1 += H-W;
				fl_polygon(x1, yy1, x1+w1, yy1+w1, x1+2*w1, yy1);
			}
		}
	}
}

/**
  Creates a new Fl_Scrollbar widget with given position, size, and label.
  You need to do type(FL_HORIZONTAL) if you want a horizontal scrollbar.
*/
Fl_Scrollbar::Fl_Scrollbar(int X, int Y, int W, int H, const char* L)
	: Fl_Slider(X, Y, W, H, L)
{
	box(FL_FLAT_BOX);
	color(FL_DARK2);
	slider(FL_UP_BOX);
	linesize_ = 16;
	pushed_ = 0;
	step(1);
}

/**  Destroys the Scrollbar. */
Fl_Scrollbar::~Fl_Scrollbar()
{
	if (pushed_)
		Fl::remove_timeout(timeout_cb, this);
}


//
// End of "$Id: Fl_Scrollbar.cxx 8864 2011-07-19 04:49:30Z greg.ercolano $".
//
